Malicious PDF — malware analysis report

Static analysis result for SHA-256 873dbc5ad86d88d2…

MALICIOUS

PDF

31.4 KB Created: 2020-08-15 14:05:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d7fd6c7b4c72e04de93a952584abc708 SHA-1: bb96106048027ac96db127c4956b42905011d04c SHA-256: 873dbc5ad86d88d26ff809da41e461ab90c9bfd2123edac947f2a7ef9b4f06b6
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a heuristic firing for a malicious redirector link, which is also present in the document body. This link, 'https://ttraff.cc/wb?keyword=conectarse%20con%20dios%20pdf%20gratis', is designed to lure users into clicking it under the guise of a free PDF download. The document also exhibits characteristics of a link farm, with numerous embedded URLs pointing to external PDFs, many hosted on Shopify. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://ttraff.cc/wb?keyword=conectarse%20con%20dios%20pdf%20gratis
    • http://files.nancyharry.com/uploads/1/3/1/4/131411688/9e3e6a831402c91.pdf
    • http://sisutazes.mysecondhandrose.com/uploads/1/3/1/3/131378950/poviw.pdf
    • https://cdn.shopify.com/s/files/1/0433/1605/2123/files/fisanovopov.pdf
    • https://cdn.shopify.com/s/files/1/0432/7541/9812/files/80413619709.pdf
    • https://cdn.shopify.com/s/files/1/0434/3123/1655/files/vs_code_format_code_settings.pdf
    • https://cdn.shopify.com/s/files/1/0437/6910/2485/files/al_quran_urdu_translation_kanzul_iman.pdf
    • https://cdn.shopify.com/s/files/1/0431/4896/8090/files/gapugibanajid.pdf
    • https://cdn.shopify.com/s/files/1/0431/4228/3432/files/administrao_pblica_brasileira_para_concursos.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/76102764406.pdf
    • https://cdn.shopify.com/s/files/1/0447/2075/0745/files/dryer_sheets_inside_shoes.pdf
    • https://cdn.shopify.com/s/files/1/0430/8851/1130/files/32322671716.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00003f40.bin
743970ccd031c473d1142c4df16210dbdab181d46844cca858cf49fd12993c02
pdf-font-stream PDF embedded font (sfnt) at offset 0x3F40 5196 bytes
font_01_sfnt_off000050f1.bin
8e2a6c439992e9457d6aa365afbaef50ffa6a70197dfa6ececb2ee971b0b8ad0
pdf-font-stream PDF embedded font (sfnt) at offset 0x50F1 9452 bytes